Coating composition



Patented July 20, 1931 UNITED STATES COATING COMPOSITION WilliamChalmers, Vancouver, British Columbia, Canada, assignor, by mesneassignments, to Riihm & Haas Company, Philadelphia, Pa.

No Drawing. Original application September 19, 1935, Serial No. 41,257,which is a continuation of application Serial No. 431,982,

February 27, 1930.

Divided and this application January 14, 1936, Serial No. 59,067. InCanada January 29, 1930 11 Claims.

This invention relates to the preparation of polymerization products ofderivatives of methacrylic acid such as methacrylic ethyl ester andmethacrylic nitrile.

Substances produced by polymerization of methacrylic ethyl ester andmethacrylic nitrile may be used as artificial resins, transparent orglass-like resins, or as plastic materials.

The polymerization products of methacrylic ethyl ester are obtained byexposing the methacrylic ethyl ester to the action of heat, sunlight, orultra-violet light, with or without the use of catalysts, such assodium, potassium, benzoyl peroxide or other organic or inorganicperoxides. The ester may be in the pure state or in solution in solventssuch as benzene.

While the polymerization may be completed by allowing the ester to standin the dark in a warm place for several weeks, it is preferred tosubject the ester to the action of the agents above mentioned in orderto accelerate the rate of polymerization so that the polymerizationproducts may be produced on a commercial scale.

The nature of the product resulting from polymerization of methacrylicester varies from that of an elastic solid to a hard glassy substance,dependent upon the duration or completeness of the polymerizationprocess. The elastic substance thus obtained may be converted into thehard glassy form by distilling ofi the unchanged v monomer at 130 C.

a smooth glassy coating of great durability and.

are thus particularly suited as a base for lacquers.

The methacrylic nitrile may be polymerized by the application of heat orby allowing the nitrile to stand with alkali metals such as thosereferred to in connection with the polymerization of the methacrylicethyl ester.

The monomeric ester or nitrile may be hydrolyzed before polymerizationby means of dilute acids or alkalies to give the methacrylic acid whichis already known to polymerize to a porcelainlike mass.

In order to more clearly illustrate the manner in which thepolymerization process above described may be carried out, the followingexamples are given:

Example 1.-Methacry1ic ethyl ester, to which about one-half of one percent of benzoyl peroxide has been added, is placed in a suitable quartzor other container and exposed to the radiation from a mercury vaporlamp. The rate of polymerization depends, of course, upon temperatureconditions and upon the intensity of the radiation. It has been foundthat when a small sample of the ester and peroxide is placed in closeproximity to a small 110 volt lamp the ester is converted into a glassysolid material in a period of time ranging from one and one-quarter toone and onehalf hours.

Example 2.The methacrylic ethyl ester may be heated in a closedcontainer from sixteen to twenty hours at 130 C. at the end of whichtime it is converted into the solid polymer. This solid may be dissolvedin all of the common organic solvents except the alcohols in which it isonly partially soluble.

Example 3.Methacrylic nitrile is treated by placing therein one per centof sodium wire and allowing the nitrile to stand for a week, at the endof which time it is entirely converted into a solid resinous mass of adark brown color. The sodium is destroyed and the dark color removed bythe addition of alcohol. The purification may then be completed bywashing with water so that the final product is alight colored resinousmaterial.

Emample 4.Polymethacrylic nitrile is dissolved in concentratedhydrochloric acid in which it forms a clear solution. The solution isthen diluted with water so that the polymethacrylic acid is precipitatedas a white flocky mass which can be filtered and dried.

While in the foregoing description reference has been made solely to thepolymerization of methacrylic ethyl ester, it will be understood thatthe process may also be applied to the polymerization of the butyl esterand other homologues, particularly the esters of methacrylic acidcontaining up to and including five carbon atoms in the alcohol radical,which esters will hereinafter be referred to as the lower aliphaticesters of methacrylic acid.

This application is a division of my copending application Ser. No.41,257 filed September 19, 1935, which application is in turn acontinuation of my application Ser. No. 431,982 filed February I claim:

1. A coating composition comprising a solu- 5 tion of polymerized ethyla-methacrylate.

2. A coating composition comprising a solution of polymerized butyla-methacrylate.

3. A coating composition comprising a solution of polymerizeda-methacrylic nitrile.

4. A coating composition comprising a solution of a polymerized loweraliphatic ester oi a-methacrylic acid.

5. A coating composition comprising a solution of a member of the groupconsisting of the 5 polymerized lower esters and nitrile ofa-methacrylic acid.

6. A coating composition comprising a solution of a polymerized productcontaining the ethyl ester of u-methacrylic acid in polymerized form.

7. A coating composition comprising a solution of a polymerized productcontaining the butyl ester 01 a-methacrylic acid in polymerized form.

8. A coating composition comprising a solution of a polymerized productcontaining a-methacrylic nitrile in polymerized form.

9. A coating composition comprising a solution 01' polymerized productcontaining a lower aliphatic ester of a-methacrylic acid in polymerizedform.

10. A coating composition comprising a solution of apolymerized'aliphatic ester of a-methacrylic acid.

11. A coating composition containing a polymerized ester of methacrylicacid.

WILLIAM CHALMERS.

